Report presenting a wind-tunnel investigation to determine the effects of leading-edge radius and maximum thickness-chord ratio on the variation with Mach number of the aerodynamic characteristics of several thin symmetrical NACA 4-digit-series airfoil sections. The variations with Mach number of the lift, drag, and pitching moment for a 4-percent-chord-thick airfoil section are not significantly affected by a change of leading-edge radius from 0.18 to 0.53 percent of the chord. Results regarding the leading-edge radius effects and maximum thickness-chord ratio are provided.

Report presenting an experimental investigation of thrust augmentation by bleedoff using a 4000-pound-thrust turbojet engine at zero flight-speed, sea-level conditions. Secondary combustion air was bled off from combustion chambers and discharged from an exhaust nozzle and water was then injected into the combustion chambers to replace the bleed-off air. Results regarding the thrust characteristics, engine power, and augmented thrust ratio are provided.

Report presenting an investigation at conditions of zero ram and seal-level pressure to determine the effect of inlet temperature and humidity on turbojet engine performance with injection of water and water-alcohol mixtures at the compressor inlet.

"Temperature surveys were made at the combustion-chamber outlets of a British Rolls-Royce Nene II engine. The highest mean nozzle-vane and mean gas temperatures were found to occur at a radius approximately 75% of the nozzle-vane length from the inner ring of the nozzle-vane assembly. Variations in engine speed, jet-nozzle area, simulated altitude, and simulated flight speed altered the temperature level but did not materially affect the pattern of radial temperature distribution" (p. 1).